A program or system intended to distinguish human from machine input, typically as a way of thwarting spam and automated extraction of data from websites.
‘The spammers are thinking up ever more ingenious ways to break the captchas.’
‘Every time you edit a page, you have to pass a captcha.’
‘I guess the spammers tools are too simplistic to even attempt to break the captcha.’
‘Their technology provides overrides for false hits on open proxies via CAPTCHA.’
‘Most Captcha programs apply mathematical transformations to their images which can potentially be reversed, thus allowing spammers to crack the Captcha.’
‘I can "solve" most CAPTCHAs in a few seconds.’
‘You could always add a CAPTCHA to the comments submission system.’
‘An estimated 6 million Captchas are completed each day, costing users 10 seconds each, wasting an overwhelming number of labor hours.’
‘Keep in mind, Captchas can most likely easily keep ahead of the state of AI for many years to come.’
‘The website employs captchas, where you guess, then type, the correct series of letters into a textbox for authentication purposes.’
‘Anecdotal evidence also suggests that CAPTCHAs are getting harder, with some effectively indecipherable.’
‘Those familiar squiggly letters are Captchas, an upgraded security measure used by many Web sites to distinguish humans from spambots.’
‘The goal of CAPTCHAs is to authenticate that there's a person sitting in front of the computer.’
‘But resourceful hackers have found ways to solve Captchas, and he has had to rethink the program.’
‘As captchas have become more sophisticated, in an arms race against algorithms designed to crack them, humans often make errors reading them.’
‘The captcha is the junk filter's last resort.’
‘"Within five years, about 200 million Captchas were being typed everyday," he says.’
‘And despite the fact that Captchas are unpopular with some people, their use is increasing.’
‘The point of the CAPTCHA is that reading those swirly letters is something that computers aren't very good at.’
‘The whole point of CAPTCHAs is to ensure that it's a real person visiting a website, not just a bot on a computer.’
Origin
Early 21st century acronym from Completely Automated Public Turing test to tell Computers and Humans Apart.
Are You Learning English? Here Are Our Top English Tips